THE I'KAK TIIHII'S. 



9 



incision, of the head Avitli its hriiiht red eves, l^ittlc by little, and 

 swayinji; backward and forward, the larva forces itself out until about 

 one-half of the body is exposed, when first the antenna^ and then 

 one l)y one the ])airs of leo;s are made fi'ee fi-oni their I'estinu; position 

 a(i;ainst the body. Swayin,<>; backward and forward, with lefi|;s and 

 antenna^ waving frantically about, the insect pushes out of the ei^ij; 

 cavity almost to its full len<=^th, whereii])on, leaning forward it eagerly 

 takes a hold with its newly formed feet, and, with a final elTort, ])nlls 

 itself free and walks rapidly away. From foin- to ten minutes are 

 required for the insect to free itself from the egg. The young insect 

 is almost transparent and the green chlorophyll ])articles taken into 

 the stomach can ])e seen through the ])ody wall. Growth is rapid 

 from the beginning. 



A very decided change takes place during the second larval stage 

 (fig. 4). In about three weeks the insect 

 reaches a size often larger than that of th<> 

 fully matured insect . It then cea.ses to feed , 

 falls to the ground, and enters the ground 

 by some crack or wormhole. It goes down 

 from 3 to 1 inches, according to the structure 

 and condition of the soil, the usual depth 

 being about 4 inches. Upon reaching a 

 secure depth, the larva hollows out for it. self 

 a tiny spherical or oblong cell or it finds an 

 exceedingly small natural cavity and shapes 

 this for its convenience. The completed 

 chamber has a hard, smooth inner wall, 

 and it is about one-twelfth of an inch long, 

 or just a little longer than the insect itself. 

 The insect here spends the greater portion fig. 5.-The pear thrips (/■.■»//(n> 

 of its life. It remains for several months w/r/):iiyinpiiorpup;i. Muoi.on- 



„ largod (origin.al). 



a quiescent, non-tooci-taking larva. Later 



the pupal changes are undergone, and lastly the adult insect appcnirs 

 before it issues forth to the tree. Larva^ collected from the ground 

 on August 28 were active, and, strange to say, green chloroi)hyll 

 matter, undigested food, wdiich had been taken into the stomach 

 several months before, was still present in their Ixxlies. The insects 

 are scattered through the soil from near the trunk to several feet 

 frcmi the tree. 



THE xvirru or. I'Itp.v. 



The writer has not been able to iletermine how long the nymph 

 stage (fig. 5) lasts, but it evidently extends over several weeks. 

 Nymphs in all stages of development were collected during May and 

 at intervals until the following February, l)ut they are most conunon 

 during December, Januan, and February. The writer has gathereil 



